Hey Gehrm,
Well, I gave the Delta Point/HAMR setup a try for 2 years. Not exactly an ACOG/RMR setup, but I will tell you my experiences. First off, I had an ACOG before, and I can say that if you practice a shit load and keep both eyes open, or close a lens cap over the front, you can very quickly apply the Bindon Aiming concept at CQB distances. When you get it down, it's pretty cool-with both eyes open, the red chevron just appears on your target. Now, where I had trouble was transitioning through multiple targets in the 25-50 yard range. Enter the Delta point. The DPoint was nice cuz I could wail on close range stuff and engage out to 25+ yards with the same zero as my optic (but with a 4inch offset, which was a bitch for 7 yard head shots!). Now, you mentioned the cheekweld. Well, the ACOG is high already, all combat optics mounts are high cuz they assume you are gonna run backups underneath. Add an extra couple inches to that with your RMR or Dpoint and that is a tall MFr. So, what I did was train on two positions: one was a standard cheekweld, and in the other, I turned my head to the right as my chin slid up my stock and i developed a "chin-weld" that would be the same point of reference every time. It was a good setup. It was accurate and at 1-400 meters, I connected with everything I aimed at with the RMR (and ACOG, fo r that matter). But I am not a smart man and I would often get confused as to which optic to be on as I negotiated the various shooting points in a big 3 gun field course! Oops! SO, I ended up putting the DPoint on a 1 oclock D-Defense mount and that was pretty damn cool. BUT, the HAMR and the DPoint were still on different planes, so I had to hunt for the optics when I transitioned. So, I took off the HAMR and put a Leupold VX-R (it was what I had on hand) in low height Badger rings and mounted it directly to my AR receiver with a Badger AR Riser/Rail Extender (no backup iron sights), and THAT setup kicked ass. Both optics were on the same plane, so I had one good, low, solid cheekweld and the only thing I had to do was to roll the gun over to the left and my optic was perfectly in view, with no shifting of my head or cheekweld. If there was a lower mount for the ACOG/HAMMER that would solve the aforementioned problem, but there's not. I bet that's why JP had the built in ACOG mount on their CTR02 upper receiver, to get it down lower and transition well with their iron backup sights.
So, the takeaways from my experiences are:
Train your ass off at varying distances so you naturally know which optic to be on, for a given distance (ACOG w RMR on top).
Train your ass off to adapt your shooting position to your equipment (ACOG w RMR on top).
Or, if you mount the primary and secondary optic seperately, try and make sure you choose teh correct height mount, or shim an existing mount, so that both optics are at about the same height so you can keep your face on your stock and move smoothly from one to the other.
Oh, and I have to give Kudos to Trijicon on their RMR. I started using an RM07 on my outlaw 3gun G17 and that thing is BAD ASS!! I love that setup. If you are used to using a red dot sight, it is a very quick and natural transition to that sight. I love that it is super tough and you can rack the slide off shit, and use it as a charging handle, and bash into barricades and it laughs at the abuse. I think the Dpoint is a little easier to see through, but I give the win to the RMR for battle toughness. Oh, and before you naysayers talk shit about how the RMR breaks or wanders when used on pistols, I have news. I was drinking beer at the Hofbrauhaus in Vegas, recently, and some nerds from Michigan came in and sat down next to my wife and I. It turns out that these nerds knew a WHOLE LOT about optics and I have it on good account that the RMR has been beefed up and that if you have ANY problems with it, send it back and they will make it better.
And after all that, I am going with the Leupold MK 1-6 with the 556 reticle! Haha!!
Whatever you choose, have fun with it.
Good info, thanks. What're people's thoughts on the ACOG + RMR combo? I have read that one has to break their cheek weld to use the RMR, the RMR is too far back for proper eye relief and that the height above the bore axis makes the RMR problematic. Do people have a better solution like RMR on offset mount?